Lowering device



March 5, 1935. p so 1,993,074

LOWERING DEVICE Filed Nov. 16, 1935 2 Sheets-Sheet 1 L l 'l llll II II- (law ATTORNEY March 5, 1935. PAYSON 1,993,074

LOWERING DEVICE Filed Nov. 16, 1955 2 Sheets-Shet 2 'l I\\ I lX Hill ilin Ipllllri'll BY C: I I I M ATTORNEY Patented Mar. 5, 1935 UNITED STATES PATENTIOFFICE LOWERING DEVICE Rudolph Payson, Flushing, N. Y. Application November 16, 1933, Serial Nc..698,241

3 Claims.

My invention relates to a lowering device; that is, a device for lowering a load by means of a rope or cable from a higher level to a lower level, under control of a friction brake, so that the load will be lowered at an automatically controlled and regulated speed.

Devices of this character are used for lowering ash cans in connection with ash hoists. Devices of this kind are also used as fire escapes in hotels, apartment houses and homes, to provide simple means for lowering a person from the room or place where the device is located to the ground or to an adjacent building, in case of fire or emergencies. There are various other places where devices of this character may be employed for lowering a load under automatically controlled speed.

The principal object of my invention is to provide a'lowering device having a sheave around which engages a rope or cable by which the load is carried and a very simple brake device automatically co-acting frictionally with the sheave to control and limit the speed of action of the sheave, so that the load is lowered gradually or at a limited speed. The main object of the present device is to simplify lowering devices and to make the construction inexpensive.

Another object is to eliminate expense of centrifugal devices for controlling the braking action and to eliminate expensive and more or less delicate parts heretofore employed where centriiugal governors were used to control the braking action. The present device is reduced to the simplest form, thereby not only reducing cost of manufacture, but also rendering the device more dependable and less likely to get out of order even where the device remains inactive over long periods. All gears are eliminated in this device.

The device is adapted for use wherever a lowering device is required and I therefore desire it to be understood that I do not intend to limit my invention to any particular use. Other advantages and objects will be set forth in the following detailed description of my invention.

In the drawings forming part of this application,

Figure 1 is a front elevation of a lowering device containing my invention, in which view the cover is removed,

Figure 2 is a sectional view taken on the line 2-2 of Figure 1,

Figure 3 is a fragmentary, a portion of a sheave,

Figure 4 is a side elevation with a portion of sectional view of the cover broken away, of a modified f invention,

Figure 5 is my invention in a modified form,

Figure 6 is a cross sectional view taken on the 5 line 6-6 of Figure 5,

orm of the an elevation of a device containing Figure '7 is an elevation of a device embodying my invention in another modified form and show ing the casing broken away to illustrate the interior parts,

Figure 8 is a sectional view taken on the line 8-8 of Figure 7, and

Figure 9 is a perspective view of the shaft employed in the construction shown in Figures '7 and 8.

I will first describe the form of the invention shown in Figures 1 to 3 inclusive. The lowering device includes a back wall 1 which may be of any particular shape and whichin the drawings consists of an upper, circular part 2 with a rectangular bottom, portion 3 extending therefrom. At various places on the plate I have shown apertures. 4 to receivev screws or bolts b'y'meansof which, the backplate may of a building be applied to a wall or to any structure on which the lowering devicejis to be mounted. Preferably, theback wall is mounted in a vertical position with the rectangular extension 3 disposed at the bottom as shown in Figure 1.

There is abraking member secure a a the back wall and it is here shownas consisting of a circularly formed plate 5 'of the shape of a segment of a cylinder and'having ears or projections 6 arranged at the upper ends and preferably at the bottom of the circular plate to receive screws or bolts 7 by means of which the brake member is secured to the back wall 1 asshown in Figure 1.

The brake member 5 can be formed as a complete circle or any lesser part of a complete circle, but I have found that if it is made semicircular as shown in Figure 1,

it will serve the purpose hereinafter described and will, nevertheless, contain no unnecessary weight.

The inner surface 8 of this braking member is circular and while I'have shown the outer surface as parallel to the inner surface and therefore circular, it is not necessary that the outer surface be so shaped, as operation of the device.

face of the sheave may, direct contact with the it has no effect on the While the braking surif desired, come into nner surface 8 of the braking member, I prefer to provide a lining member 9 seated against the inner curved surface 8 of the braking member and the inner surface 10 of this lining member is circular.

This

ill

member may be made of fibre, leather or any other suitable material. The lining member may be secured to the braking member by means of rivets 11 having their heads 12 countersunk on the inner surface of the lining member, the rivets passing through the lining member and through apertures in the brake member 5 and the heads 13 are turned over against the member 5 as shown in Figures 1 and 2.

The sheave 14 consists of an annular member having a peripheral groove 15 to receive a rope or cable 16 in the groove. Preferably, the V shaped walls of the groove are provided at intervals with small ribs or projections 17 against which the rope or cable presses and which serves to prevent the rope or cable from slipping on the sheave.

The sheave is mounted to revolve on a circular member or a shaft 18. This latter member has a rectangular central opening 19 through which projects a support 20 which is secured to the back wall 1 by means of a reduced portion 21 extending through an aperture 22 in the back wall and having a head 23 upset or riveted against the back wall to rigidly secure the member 20 against the same. If desired, the member 20 may be welded directly to the back wall. I have shown the member 20 as rectangular in cross section in Figure 1, and it fits in the rectangular opening 19 of the member 18 but its vertical dimension is somewhat less than the opening 19 in order that the member 18, together with the sheave which is mounted thereon, may have a slight vertical movement in relation to the fixed member 20.

The several parts are secured in assembled position by the bolt 24 which is threaded into the stationary member 20 the head of the bolt securing the washer 25 against the face of the stationary member 20. The washer is sufficiently large in diameter to extend across the left hand face of the member 18 in Figure 2 and partly across the left hand face of the sheave 14 in this same figure. This washer, therefore, prevents the annular member 18 and .the sheave from moving sidewise off the stationary member 20 and they cannot move to the right because of the presence of the back wall 1. It will be apparent that the member 18 has a slight vertical movement in relation to the stationary member 20 but it cannot revolve because the stationary member has a square section and it, engages in the rectangular opening 19.

The member 16 may be a rope or a cable or it may be a rope having a metal core 25 as shown in the drawings. One run of this rope or cable passes upwardly at the left in Figure 1 through an aperture 26 in the guiding block 27 which is bolted to the back plate 1.

The rope passes through an angular aperture 28 in both the brake member and the lining member and then passes around the groove 15 of the sheave. The other run of the rope or cable, at the right in Figure 1, passes downwardly through a corresponding aperture 29 in the lining member and the brake member and'then passes downwardly through a second aperture 30 in the guiding block. The guiding block determines the extent of the engagement of the rope or cable with the sheave and prevents it from disengaging from the sheave.

It is preferable, although not necessary, to provide a cover for enclosing the working parts of the device to exclude dirt and moisture. For this purpose I have shown a circular cover 31 created between the friction surfaces having a tongue 32 entering a slot in the back Wall 1 and having a snap device 33 at the top for engaging in the notch 34 of the cover so that these two parts detachably secure the cover to the back wall. There are slots 35 formed in the cylindrical wall of the cover to receive the two runs of the rope or cable.

It will be noted that the sheave has cylindrical surfaces 36 on each side of the notch 15 in which the rope or cable engages and these surfaces, which are in effect friction surfaces, rest against the brake lining 9.

Operation The rope or cable is threaded through the guide block 2''! and around the sheave as shown in Figures 1 and 2, and as described above, the rope or cable lies in the groove 15 of the sheave and engages the projections 17 so that it cannot slip in relation to the sheave. Assuming that a weight is attached to the right hand run of the rope or cable in Figure 1 by means of a hook, loop, or other suitable arrangement, and that it is desired to lower this weight, the device will operate as follows:

By the action of the weighted body, whatever it might be, the right hand run of the rope or cable in Figure 1 tends to move downwardly and this will cause the sheave to move clockwise in Figure 1 while the body is being lowered. The friction surfaces 36 of the sheave will be pressed down against the inner surface 10 of the brake lining 9 which latter is secured to the inner surface of the brake member 5 and the friction of the sheave and the brake lining will resist the turning of the sheave and thereby limit the speed at which the weight is lowered, so that the latter moves down gradually. The friction generated between the sheave and the brake lining will depend to a great extent upon the weight of the body which is being lowered on the rope or cable.

If the weight of the body being lowered is comparatively light, there will be less friction be tween the sheave and the brake lining, whereas if the weight of the body is greater, the friction created between the sheave and the brake lining will be greater, offering greater resistance to the movement of the sheave. It will be apparent, therefore, that the friction controlling the lowering of the load or body will be more or less proportional to the weight of the body. Bodies of different weights will therefore be lowered at substantially the same speed or at least at such speeds as will prevent the load from striking the ground or platform with a sharp or sudden blow. For all practical purposes the friction between the sheave and the brake lining will permit the load to move downwardly at a safe speed. This construction and arrangement eliminates the necessity of using centrifugal governors for controlling the lowering of the load.

The device is reversible in its action. That is to say, if a load has been lowered on the right hand run of the rope or cable and the free end of the left hand run has been brought to an elevated position, a body may be attached to this run of the rope for lowering. When the body moves downwardly the sheave will be revolved counter-clockwise in Figure 1. The friction action of the sheave on the brake device will be the same as in the first described operation.

In Figure 4. I have shown a modified form of the invention. Herein the sheave 37 has a friction surface 38 on one side only of the groove 39 'and therefore only thi'ssurface 38 engages the brake lining member. In all other respectsthis form ofthe-inventionmay'be the same as-the one first described. I

In the construction shown'in Figures and 6 there is a backing" plate or-base 41 having the guide block 40 attached thereto and through which the rope 42 passes in leading to and re turning from the sheave, thesame as in the pre vious construction. In this instance 5 the sheave 43 is an annular member adapted to revolve without an axle and between the' plane of the wall'4l and a strap 44 which is secured-across the posts or spacers45"which project laterally from the base member 41 and the strap 44 is heldon these posts by the screws46. The verticalspace between the back wall 41 and the strap 44 is sufficient to allow the sheave 43 to revolve freely between these parts without undue lateral play of the sheave. The rope 42 engages and passes around in the peripheral groove 47 as in the previous form of the invention and the surfaces 48 on opposite sides of the peripheral groove are friction surfaces which engage the brake.

Above the sheave there is a rigid post 49 either fixed to or formed integral with the back wall 41 and it extends laterally from this back wall over the center of the sheave 43.

There is a continuous strap 50 of flexible material such as a strap of steel, and this strap extends downwardly and passes entirely around the sheave and thence upwardly, so that the ends 51 overlap each other at the post 49, the overlapping ends of the straps being secured together by rivets 52 or other suitable means. One or more screws 53 may be used to pass through an aperture or apertures in the pverlapping ends of the strap 50 and entering a threaded aperture in the post 49 to maintain the strap in proper hanging position from the support 49.

The brake lining 54 is attached to the inner surface of the strap 50 so that it extends around a major portion of the sheave but terminates as shown in Figure 5, some distance below the support 49, so as to leave a gap. In this construction the sheave rests upon the brake lining 54 which is attached to the strap 50 so that the weight of the sheave rests on the strap.

The operation of this device is as follows: When a weighted body is attached to one end of the rope or cable 42 to be lowered, the sheave is revolved by the rope and its friction surfaces 48 resting upon the inner surface of the brake lining 54 presses or hangs down upon the strap 50 which itself is supported on the member 49. As the strap 50 is bendable, it and the brake lining will conform to the sheave throughout the major portion of its circumference and the pressure between the sheave and the brake lining will conform to the weight of the body which is being lowered.

' As the body being lowered presses downwardly,

the friction between the sheave and the brake lining will conform to the weight of the body being lowered so that where a relatively heavy body is being lowered the friction will be greater, and conversely, when a light body is being lowered the friction between the sheave and the brake lining will be relatively less.

This variation in the friction between the sheave and the brake lining will be such as to cause the body to be lowered at practically the same speed, regardless of its weight. In other words, the device automatically lowers the body v -'the same"speed;flregardless of friction surfaces of thesheave throughout more thanhalf the circumference of the sheave. Furthermore; 1 the supporting member, -.to wit, the strap 50 is'pliable and willconfo'rm to the periphe cry of the sheave and it engages the major pore tion of the circumference. of the latter. 1 This form of support 'causesethesheave to-operate morecnearly at a uniform1speed :when bodies of different relative weights. are being-lowered.

In this construction the studs 45 are arranged closeto if not in contact with, thestrap 50, onja horizontal line with the axis of the sheave, as shownin Figure '5. When the weight of the body being loweredis carriedrbyeither the right'or left run of the rope 42' there is a'-tendencyfor the sheave and the strap to swing to the right or left, according to which end of the rope the lowering body is attached. The posts 45 prevent the sheave and the strap 50 from swinging either right or left, thereby performing the same function as would a shaft extending through the sheave.

In Figures '7, 8 and 9 I have shown another modification of my invention. In these several views the construction of the supporting strap, brake lining, and sheave are the same as in Figures 5 and 6, except that the sheave has a smaller central opening, so that it fits over the short shaft 55. This shaft has cutouts 56 at each end to form the bearing members 5'7 having straight sides.

This shaft extends between the back plate 41 and the cover plate 58, these two members having apertures 59 opposite each other. The apertures 59 are proportioned to receive the bearing members 57 of the shaft therein and to permit the shaft to rise and fall vertically in these apertures, but the apertures fit the sides of the bearings 5'7 so that the shaft cannot revolve.

In Figures 7 and 8 I have shown two idler rollers 60 mounted on pins 61. These rollers have peripheral grooves 62 in which the rope 63 engages. These idler rollers serve to guide the rope to and from the sheave with less chance of frictionthan in the guide block 40 in the previous construction.

It will be apparent that my present invention provides a much simpler lowering device than those heretofore used.v No centrifugal governor device is necessary to apply the braking friction. All gears are eliminated in the present device. As soon as the load is placed on the rope the friction device is at once effective. The device will operate for years without requiring repairs.

Having described my invention, what I claim is:

1. In a device of the class described, a support, a shaft member stationarily mounted on said support and projecting therefrom, a sleeve mounted on said shaft in such manner that said sleeve may rise or fall in relation to the shaft but be held non-revolvable thereby, an annular sheave revolvably supported on said sleeve, a rope or cable engaging around the sheave and by which a body is adapted to be lowered, and a brake member mounted to support said sheave and against which the sheave is pressed by the lowering body whereby the brake member will frictionally resist revolution of the sheave in accordance with the weight of said body.

2. In a device of the class described, a support, a shaft mounted thereon and projecting laterally therefrom, said shalt having a polygonal cross section, a sleeve having a bore therethrough of polygonal cross section and of greater dimension in one direction than the diameter of said shaft, said sleeve being mounted'over said shaft whereby the sleeve is non-revolvable on the shaft but is permitted to move vertically in relation thereto, a sheave of annular shape mounted to revolve on said sleeve, a rope or cable engaging around the sheave and by means ot'which a body is adapted to be lowered, a washer secured to one end of said shaft and extending laterally beyond the diameter of said sleeve and extending at least partly over the face of said sheave to secure the sleeve and sheave in assembled position on said shaft, and a brake member mounted to support said sheave and against which the sheave is adapted to be pressed by said body' whereby the brake member will frictionally resist revolution of the sheave in accordance with the weight of the body being lowered. V

' 3. In a device of the class described, a base plate or support, a member projecting laterally therefrom, a bendable strap forming a complete loop and means for attaching the same to said lateral support, a brake lining inside said strap, a sheave having a friction surface engaging the inner surface of said brake lining and mounted to revolve within the brake lining and strap, a rope or cable engaging around the sheave and by means of which, a body is adapted to be lowered, means disposed horizontally at opposite sides of the sheave and strap to limit the lateral swing of said sheave, and a guard strap connected between said limiting means and extending across one face of the sheave whereby the sheave is revolvably confined laterally'between said base plate and said strap.

RUDOLPH PAYSON. 

